Could someone tell me how to color two different edges between the same two vertices with a different color? The last time a related question was asked is 4 years ago, so I am wondering if the following can sort of be made to work now ... This is what I have tried:

1) {Style[DirectedEdge[1,2],Red],Style[DirectedEdge[1,2],Green]}//Graph

I would like the edges in the above multigraph to be red and green, however this makes them all red. If I use EdgeStyle in the usual way, the edges take the last color that appears instead of the first one. I have never had to do this, surprisingly, and I thought it would be a cinch (I know the graph functionality of M quite well) but to my surprise I couldn’t make this work. So help will be appreciated. Perhaps a more complex fix is needed ???

I wonder also, if this is not easy to achieve, whether there is igraph functionality for it. I am not thoroughly familiar with the package

Thank you in advance.

  • $\begingroup$ As of v12 this is still impossible out-of-the-box. Try this answer in the (duplicate?) q/a Graph: Coloring parallel edges individually. $\endgroup$ – kglr Aug 26 '19 at 15:59
  • $\begingroup$ @kglr Thank you, I guess that will have to do! $\endgroup$ – EGME Aug 26 '19 at 16:03
  • $\begingroup$ @kglr Hmmm, I am trying to make your original answer work for just two edges, as in my question, but I can’t ... well, let’s see what develops ... might I ask for help if I can’t make this work? $\endgroup$ – EGME Aug 26 '19 at 16:17
  • $\begingroup$ @kglr Ok, I got it to work, although I don’t understand how it works ... $\endgroup$ – EGME Aug 26 '19 at 16:20
  • $\begingroup$ @kglr But it only works for two edges :( oh well ... $\endgroup$ – EGME Aug 26 '19 at 16:47

Now this works in Mathematica 12.1:

{Style[DirectedEdge[1, 2], Red], Style[DirectedEdge[1, 2], Green]} // EdgeTaggedGraph

enter image description here

  • $\begingroup$ Thanks, this should be quite useful ... $\endgroup$ – EGME Apr 7 '20 at 8:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.